高强度钢高效磨抛用钎焊金刚石磨盘的制备及性能研究

发布时间：2018-08-16 08:25

【摘要】：高强度钢在航空航天、船舶制造、化工设备等领域应用越来越广泛,目前主要利用树脂砂轮片进行表面磨抛处理,暴露出材料去除率低、砂轮易损耗破碎、气味粉尘大等问题。为解决上述问题,论文利用钎焊技术将金刚石焊接在钢基体表面制作磨抛工具,期望利用钎焊金刚石工具磨粒结合强度高、磨粒出露高、散热效果好的优势实现高强度钢的高效磨抛。本文完成的创新性研究工作主要包括:(1)为获得磨粒良好出露、焊料层厚度均匀的钎焊效果,提出大粒度合金焊料真空钎焊金刚石工艺构想并建立了几何模型,得出金刚石最优钎焊效果的大粒度合金焊料与金刚石粒度关系方程组,并求得基于合金焊料润湿角的实际解。在此基础上确定了新型磨粒布料工艺,并建立了金刚石磨粒与焊料合理钎焊的几何模型,得到了具有理想钎焊效果的金刚石粒度与焊料粒度匹配公式。通过公式计算,粒度为50目的球状颗粒Ni-Cr合金焊料钎焊金刚石的最优粒度为60目。钎焊试验结果表明:合金焊料对金刚石有较好的爬升效果,平均包埋高度约为金刚石粒径的30%。(2)通过分析树脂砂轮片磨损特点对钎焊金刚石磨盘基体进行结构化设计,结合ANSYS有限元仿真分析以及磨抛受力模型,确定了磨盘基体优选尺寸。通过冲压工艺以及外圆倒角工艺控制基体形位尺寸精度,结合盘状零件确定了钎焊金刚石磨盘基体加工工艺。(3)基于磨盘磨抛条件与磨粒参数特性,对磨粒地貌优选机理进行分析,确定了磨抛斜面均布或点(簇)状有序、磨抛外缘密排均匀、磨抛平面叶序簇状排布的磨粒地貌。通过激光打孔工艺实现了金刚石磨粒分区域的有序排布,贴敷性好的模板材料可实现对平面、弧面的有效排布。(4)综合利用以上研究成果研制出钎焊金刚石磨盘,对AH36船用高强度钢进行磨抛加工试验。与同规格常规树脂砂轮片相比,平均材料去除率提高40%左右,磨抛寿命提高11倍以上。磨粒磨损状态与磨屑形貌对比分析表明,钎焊金刚石磨盘单颗磨粒去除量大,磨削点温度低于树脂砂轮片,不易形成熔融小球,显著减少了火花的产生。(5)基于弹性隔振原理,设计了磨盘隔振器;基于阻尼减振降噪原理,设计了自由阻尼结构磨盘。噪声与振动试验结果表明:与同规格100mm树脂砂轮片相比,未附隔振器的磨盘振动值高31.6%,附隔振器的磨盘振动值高4%;自由阻尼结构磨盘振动值较树脂砂轮片低31.3%,噪音值低7.8%。
[Abstract]:High strength steel is more and more widely used in aerospace, ship manufacturing, chemical equipment and other fields. At present, resin grinding wheel is mainly used for surface grinding and polishing treatment, which exposes problems such as low material removal rate, easy wear and tear of grinding wheel, and large smell dust and so on. In order to solve the above problems, the paper uses brazing technology to weld diamond on the surface of steel substrate to make grinding and polishing tools. The advantage of good heat dissipation effect is to realize high efficiency grinding and polishing of high strength steel. The innovative research work accomplished in this paper mainly includes: (1) in order to obtain the brazing effect of fine abrasive particles and uniform thickness of solder layer, the technological conception of vacuum brazing diamond with large grain size alloy solder is put forward and the geometric model is established. The equations of the relationship between large grain size alloy solder and diamond grain size are obtained, and the practical solution based on the wetting angle of alloy solder is obtained. On the basis of this, the new abrasive distribution technology is determined, and the geometric model of reasonable brazing between diamond abrasive and solder is established, and the matching formula of diamond particle size and solder particle size with ideal brazing effect is obtained. The formula shows that the optimum particle size of Ni-Cr alloy brazing diamond is 60 mesh. The results of brazing test show that the alloy solder has a good climbing effect on diamond, and the average embedding height is about 30% of the diameter of diamond. (2) by analyzing the wear characteristics of resin grinding wheel, the matrix of brazed diamond disc is designed structurally. Combined with ANSYS finite element simulation analysis and grinding force model, the optimum size of grinding disc matrix was determined. The machining process of brazed diamond disc matrix is determined by stamping process and outer circle chamfering process to control the precision of matrix dimension. (3) based on the grinding conditions and abrasive particle parameters, the machining process of brazed diamond disc matrix is determined. Based on the analysis of the optimum selection mechanism of abrasive particles, the abrasive geomorphology with uniform distribution or point (cluster) order of grinding and throwing slope surface, dense and uniform arrangement of grinding edge and cluster-like arrangement of grinding plane leaf sequence is determined. The ordered arrangement of diamond abrasive particles is realized by laser drilling process, and the effective arrangement of plane and arc surface can be realized by the template material with good adhesion. (4) the brazed diamond grinding disc is developed by synthetically utilizing the above research results. The grinding and polishing test of AH36 marine high strength steel was carried out. Compared with the conventional resin grinding wheel of the same specification, the average material removal rate is increased by about 40%, and the polishing life is increased by more than 11 times. The comparative analysis of abrasive wear state and wear debris morphology shows that the single abrasive particle removal amount of brazed diamond disc is large, the grinding point temperature is lower than that of resin grinding wheel, and it is not easy to form a molten ball. (5) based on the principle of elastic vibration isolation, it is difficult to form a molten ball. (5) based on the principle of elastic vibration isolation, The vibration isolator of grinding disk is designed, and the free damping structure grinding disk is designed based on the principle of damping vibration and noise reduction. The results of noise and vibration test show that the vibration value of the disc without vibration isolator is 31.6 higher than that of the same size 100mm resin grinding wheel, and the vibration value of the disc with vibration isolator is 4, and the vibration value of the free damping structure grinding disc is 31.3 lower than that of the resin grinding wheel, and the noise value is 7.8.
【学位授予单位】：南京航空航天大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TG74

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